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Equipment Discussions >> Mounts

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Per Frejvall
sage


Reged: 09/28/12

Loc: Saltsjöbaden, Sweden
Re: 10Micron new [Re: EFT]
      #6314317 - 01/15/14 12:45 PM

That is 2.1"/px with 3-, 5- and 10-minute exposures. Emphasis on 5-minute ones.

When you move much below the seeing the images are not that retty. Bloaty stars. If you go much above you will get blocky stars. I find the 1-2"/px range most pleasing for the eye.

/per


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Per Frejvall
sage


Reged: 09/28/12

Loc: Saltsjöbaden, Sweden
Re: 10Micron new [Re: EFT]
      #6314360 - 01/15/14 01:01 PM

This one was shot using the GM1000HPS, the Tak and the QSI-683. Filters from Astrodon. All subs are 10 minutes in length, BIAS and flats. Again from the balcony, and as always unguided.

The balcony has a disadvantage in the terrain mask which extends to 45 degrees to the south. I tend to do only near-zenith objects from there and that works fine. The mounts have no problems with meridian flips and I do not let them run through the meridian at all. Capture is with ACP/MaximDL/FocusMax.


All the best,

Per



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Per Frejvall
sage


Reged: 09/28/12

Loc: Saltsjöbaden, Sweden
Re: 10Micron new [Re: Per Frejvall]
      #6314365 - 01/15/14 01:06 PM

Crop, full res but JPG... Why can I not post images larger than 200KB when they are hosted on my own servers? Anyone know?

/per



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EFT
Vendor - Deep Space Products
*****

Reged: 05/07/07

Loc: Phoenix, AZ
Re: 10Micron new [Re: Per Frejvall]
      #6314383 - 01/15/14 01:14 PM

Quote:

Crop, full res but JPG... Why can I not post images larger than 200KB when they are hosted on my own servers? Anyone know?

/per






Per,

There is a strict file size limit. The best thing to do is post your "thumbnail" of the image and turn that into a link to your full-resolution image off-site.


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R Botero
Pooh-Bah


Reged: 01/02/09

Loc: Kent, England
Re: 10Micron new [Re: EFT]
      #6314493 - 01/15/14 01:56 PM

Compelling examples Per!
Roberto


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Pinbout
Postmaster
*****

Reged: 02/22/10

Loc: nj
Re: 10Micron new [Re: Per Frejvall]
      #6314781 - 01/15/14 03:52 PM

Quote:

Why can I not post images larger than 200KB when they are hosted on my own servers? Anyone know?





its an old spec. but they now let you post larger than 800x800. you have to compress the *&(& out of the file.

but for some reason its making it the thumbnail and not the full size.

its suppose to be considerate to those in other countries with much slower download connection[like cleveland]. ie an old spec.




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Whichwayisnorth
Pooh-Bah
*****

Reged: 07/04/11

Loc: Southern California
Re: 10Micron new [Re: Pinbout]
      #6314802 - 01/15/14 04:00 PM

I am going to ask my wife to stop by and buy lotto tickets. Or I need to mortgage my house. 10micron mounts are looking amazing! I think I am moving it to the top of my dream mount list.

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freestar8n
Post Laureate
*****

Reged: 10/12/07

Re: 10Micron new [Re: Per Frejvall]
      #6315839 - 01/16/14 03:48 AM

Quote:

How does a galaxy of that size look with half an arcsecond per pixel? Not so pretty




When the mount is good and seeing is good and focus is good and guiding is good - for me I want the highest resolution possible. There is a recurring theme in CN for comparing optical/mount/guiding performance based on a "pretty" picture - when it is much more informative to use quantitative performance metrics such as fwhm. You can always show a pretty picture with whatever processing in addition - but the most information would come from raw linear sub-exposures at high res - and 0.5" per pixel is not small at all for a high end mount.

Although people will say "I am at the limit of my seeing" - it doesn't really matter in terms of presenting performance results. All you can conclude is that the mount achieved 3" fwhm - and you have no idea what it is capable of achieving. If it achieves 1" fwhm in a 20m exposure - that's great and good info - but if it is 3" and you don't know if it is due to seeing, guiding - whatever - you just don't have good info.

I am not clear on when I will get a high end mount but I am certainly considering the options, and I'm interested to hear comparisons of software and usability. But I also want to see high res unprocessed sub-exposures, along with fwhm's. And the fwhm's are most accurately measured, and the star sizes and shapes visually assessed, with very small pixels, in arc-seconds.

For me, M33 looks nice in big wide field shots - but high res close ups of structures within the galaxy can look amazing - not just for what they are - but for being captured in detail, in the raw data, with good equipment and technique.

Frank


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EFT
Vendor - Deep Space Products
*****

Reged: 05/07/07

Loc: Phoenix, AZ
Re: 10Micron new [Re: freestar8n]
      #6316088 - 01/16/14 09:46 AM

Quote:

Quote:

How does a galaxy of that size look with half an arcsecond per pixel? Not so pretty




When the mount is good and seeing is good and focus is good and guiding is good - for me I want the highest resolution possible. There is a recurring theme in CN for comparing optical/mount/guiding performance based on a "pretty" picture - when it is much more informative to use quantitative performance metrics such as fwhm. You can always show a pretty picture with whatever processing in addition - but the most information would come from raw linear sub-exposures at high res - and 0.5" per pixel is not small at all for a high end mount.

Although people will say "I am at the limit of my seeing" - it doesn't really matter in terms of presenting performance results. All you can conclude is that the mount achieved 3" fwhm - and you have no idea what it is capable of achieving. If it achieves 1" fwhm in a 20m exposure - that's great and good info - but if it is 3" and you don't know if it is due to seeing, guiding - whatever - you just don't have good info.

I am not clear on when I will get a high end mount but I am certainly considering the options, and I'm interested to hear comparisons of software and usability. But I also want to see high res unprocessed sub-exposures, along with fwhm's. And the fwhm's are most accurately measured, and the star sizes and shapes visually assessed, with very small pixels, in arc-seconds.

For me, M33 looks nice in big wide field shots - but high res close ups of structures within the galaxy can look amazing - not just for what they are - but for being captured in detail, in the raw data, with good equipment and technique.

Frank




I'm sure that this is a great way to evaluate performance and you can demand this kind of data, but are you willing to pay someone for their time and time on their equipment to do this? Probably not (but you would if you were renting a scope to do this yourself). Are you willing to accept results given to you by the manufacturer? Probably not (results directly from manufacturers or people closely associated with them are almost always viewed with a jaundiced eye around here and that's when people are being kind). It's all fine and dandy to say that you want this information, but why should someone who wants to spend their time taking "pretty pictures," instead spend their time conducting and academic experiment? Most people are interested in the results they want, not proof of how they got there or proof that they have the best performing mount around. People who buy this type of equipment do so because they are convinced of its excellent performance. They do not buy this type of equipment so that they can convince other's of its excellent performance (except when they feel the need to justify their purchase to others).

You may think that high resolution images of part of M33 are great, but if no one else is interested in that, then you will have to provide examples for yourself and if the only way you will be convinced of performance is to have those examples, then you may never buy a mount. If you can only find example of what you want from one scope manufacturer (because someone felt the need to justify their purchase or show the world just how good their mount is), then I guess you will be limited to just that brand and close yourself off to other, potentially better, brands.

It just doesn't make sense to demand results that the average person has no interest in or time for in order to make a decision of your own. I've seen you make this demand many times and you get very few, if any, results that satisfy you. If very few people are interested in these type of results then what is the incentive for even the manufacturer to provide these results (not that anyone would believe them anyways)?


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freestar8n
Post Laureate
*****

Reged: 10/12/07

Re: 10Micron new [Re: EFT]
      #6316313 - 01/16/14 11:40 AM

I'm not demanding anything. I'm responding to the claim that a) high res images of galaxies are not pretty (I disagree) and b) processed images convey mount performance (I disagree). If someone wants to convey performance of a system - I am not asking for more work - I am asking for *less* work - by simply showing a raw sub-exposure rather than something processed. I don't think I'm unusual in requesting this - because people have been doing it for years.

I am involved in free autoguiding software, so I need to convey that it is working well - and I do this with many images on the MetaGuide site. Show a processed image, state the fwhm in arc-seconds, and show a close up of a known region in a sub-exposure with a linear stretch.

For some reason people are focused on processed final images to convey performance, and the key quantitative information compared and plotted is - periodic error. I think that performance should be conveyed by quantitative results from the sub-exposures since everyone ultimately relies on raw sub-exposures to build an image.

There are many ways an image can have impact, and resolution is one of them - both in revealing structures within the objects, and in revealing otherwise blurred background details such as small galaxies. If you aren't interested in resolution, then a small, fast refractor on a mid-range mount guided by a guidescope will do very well.

I'm puzzled that you think people don't regard detail and resolution as important, or that no one is interested in structures within M33, such as the NGC objects it contains. Resolution is a prime reason to get a high end mount in the first place - and the results they yield would then allow performance-based comparison.

Of course if someone doesn't want to convey mount performance that is perfectly fine. But if they do want to - I'm just saying I prefer to see more raw information and at high-res.

Frank


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EFT
Vendor - Deep Space Products
*****

Reged: 05/07/07

Loc: Phoenix, AZ
Re: 10Micron new [Re: freestar8n]
      #6316515 - 01/16/14 01:21 PM

Quote:

I'm not demanding anything. I'm responding to the claim that a) high res images of galaxies are not pretty (I disagree) and b) processed images convey mount performance (I disagree). If someone wants to convey performance of a system - I am not asking for more work - I am asking for *less* work - by simply showing a raw sub-exposure rather than something processed. I don't think I'm unusual in requesting this - because people have been doing it for years.

I am involved in free autoguiding software, so I need to convey that it is working well - and I do this with many images on the MetaGuide site. Show a processed image, state the fwhm in arc-seconds, and show a close up of a known region in a sub-exposure with a linear stretch.

For some reason people are focused on processed final images to convey performance, and the key quantitative information compared and plotted is - periodic error. I think that performance should be conveyed by quantitative results from the sub-exposures since everyone ultimately relies on raw sub-exposures to build an image.

There are many ways an image can have impact, and resolution is one of them - both in revealing structures within the objects, and in revealing otherwise blurred background details such as small galaxies. If you aren't interested in resolution, then a small, fast refractor on a mid-range mount guided by a guidescope will do very well.

I'm puzzled that you think people don't regard detail and resolution as important, or that no one is interested in structures within M33, such as the NGC objects it contains. Resolution is a prime reason to get a high end mount in the first place - and the results they yield would then allow performance-based comparison.

Of course if someone doesn't want to convey mount performance that is perfectly fine. But if they do want to - I'm just saying I prefer to see more raw information and at high-res.

Frank




But you are demanding this so that you can make your decisions either on purchasing a premium mount or on your software. You continue to ask people here and elsewhere for information that they don't supply or you are not satisfied with. This either means that people don't have the information to provide you, they don't want to provide it, or that there is no way to satisfy your need. If it was so easy to provide this information, then its seems to me that you would have tons of it by now. It would appear that the images on your website are only those that you have taken in order to support the operation of your software. Again, what is the incentive for anyone else to provide you with information from their mount using different software, particularly when you have a conflict of interest on this yourself. Should someone post an image so that you can say your software would produce something better? In addition, you fall into the same problem that other manufacturers and people associated with them. That is, anything you present in regards to results will be looked at as being biased.

The average imager is focused on final images to convey performance because it is only the final images that matter to them. Why should they focus on anything else? So that they can feel bad that there may be a "better" mount out there that will give them the exact same final images?

It is not just sub-exposures of a wide-field object that you want. It is high resolution sub-exposures of parts of the larger object that people tend to image as a whole. You want people to provide close-ups of a known region in a sub-exposure with a linear stretch. Again, this is more than just posting a sub-exposure on the forum (in low resolution by necessity) for you to look at. There is simply no incentive for the average imager to capture or provide this information. If you want this information, then you have to go to the manufacturer and convince them to provide it, just like on your site.

People certainly do regard detail and resolution as important. There is no question of that since it makes for good final images. But you want something that people are either unwilling or unable to supply as evidenced by the continued lack of response to the demand. You want people unassociated with the manufacturers to provide information that is just as likely (if not more likely) to get pounded on as insufficient or an example of just how bad their expensive equipment is as it is to get praised for quality. Why should anyone open themselves up to that to serve your needs when they are completely satisfied with their results and not in doubt of the quality of their equipment?

To the average person, the best indication of mount performance is the final result. While this may not be the best indication or the most scientific measure, it really is what matters to most people. That does in fact mean that some people can satisfy their imaging goal by simply using a small refractor on a low-end mount. If you provide someone fwhm information on two different mounts and then show them images taken from those mounts that essentially provides the same result when printed out in 8x10 or looked at on a computer screen, why should they really care, or more important, why should they feel the need to provide this information?

The other problem that is completely ignored here, is that the mount is only a part of the complete imaging system and imaging process. The results provided from two different people, using two different mounts, scopes, cameras, etc., in two different locations, at two different times and shooting two different targets, may well be meaningless in the scheme of things. The information that you really need in order to draw the conclusions you want would have to be obtained from one person, using different mounts with everything else the same, at the same location and preferably the same time. That's simply not (and probably never) going to happen (unless one of the big publications decides to do it and then they will be questioned as being bias based on their advertising revenues).

For what you want you are really the only person that can provide it (or at least get near to providing it). You need to borrow, rent or buy and mount and test it out and decide whether you like it or not. If not, then you move on to the next one. Before that, you will most likely have to rely on the information that the manufacturers provide and their level of honesty and integrity. Interestingly, just looking around at a few premium mount manufacturer's websites, I do not see them providing fwhm information on the mounts they make. This suggests that they do not consider this information worth providing (or if you want to be cynical, it is information that makes them all look bad in some way).

I would probably be happy to personally provide this type of data for the mounts I deal with or work on if I felt it were meaningful and not somehow misleading (i.e., convincing people to buy something based on meaningless numbers only). I would do so mostly out of curiosity and the fact that I am not involved in imaging otherwise so it wouldn't take me away from producing other images. But I am not really an imager myself so even I doubt my own results, I don't have the time to work all day and play all night, I don't really have the proper imaging equipment beyond the mount, and scopes, and I am connected to the manufacturers, so that any data I would provide would be considered suspect by many people (and thus a waste of my time).

I don't see any good way around getting you what you want unless someone volunteers to take the time to produce it for you.


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korborh
professor emeritus
*****

Reged: 01/29/11

Re: 10Micron new [Re: EFT]
      #6316539 - 01/16/14 01:35 PM

Ed, if someone has the final image, they also have the individual RAW sub-exposures. How exactly is that harder to post than the final image? It easier - no processing, no nothing just the RAW sub.
You mention about the different variables that can make comparison and root-causing fwhm degradation difficult. Well, using RAW unprocessed images one is reducing some of these variables. The simple fact is without "measuring" the result in RAW images one cannot really quantify the quality of the data. And people buy high-end mount to improve the quality of the data. Mount manufacturers do show FWHM. Roland had posted a screenshot of the RAW sub-exposure and FWHM from his image with a Mach1 from the first batch to showcase the quality of the result.


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EFT
Vendor - Deep Space Products
*****

Reged: 05/07/07

Loc: Phoenix, AZ
Re: 10Micron new [Re: korborh]
      #6316629 - 01/16/14 02:21 PM

Quote:

Ed, if someone has the final image, they also have the individual RAW sub-exposures. How exactly is that harder to post than the final image? It easier - no processing, no nothing just the RAW sub.
You mention about the different variables that can make comparison and root-causing fwhm degradation difficult. Well, using RAW unprocessed images one is reducing some of these variables. The simple fact is without "measuring" the result in RAW images one cannot really quantify the quality of the data. And people buy high-end mount to improve the quality of the data. Mount manufacturers do show FWHM. Roland had posted a screenshot of the RAW sub-exposure and FWHM from his image with a Mach1 from the first batch to showcase the quality of the result.




I agree that, on its face, it seems that it should be that easy to get this information (at least in regards to any image in general), but for some reason that doesn't happen. So what is the reason? I think that it may in large part be related to the poor reception that many people get when they provide anything other than a good final image. In addition, the request is more specific. He wants a high resolution image of a sub-region of something like M33 that many people images as a whole.

Certainly using the raw images reduces some of the variables and simplifies the data by removing the effects of processing, but it does not eliminate them and the failure to consider the imaging system and conditions as a whole is one of the common mistakes that people make. It bothers me every time someone takes a single number (PE being the most common) and says that decisions on different mounts can be reduced down to that simple number.

A lot of people actually buy high end mounts to make the process of collecting data more easy. Good quality data can be captured in many different ways (the current argument between guided and unguided imaging on premium mounts is an example), but some equipment, particularly mounts, may make the capture of that quality date easier or more while not necessarily providing any better data. Other examples are cameras with less noise, scopes with faster optics. These don't necessarily provide better data, they provide the same data faster and easier because your exposures can be shorter and you might eliminate the need for darks or flats. I would say that the reality is that the quality of data is more dependent on the scope and camera used whereas the ease of collecting that data is more dependent on the mount because it may do things like eliminate the need for guiding, allow for less aggressive guiding, allow for longer exposures in general, etc.

Like I said, in at least a quick look around, I could not find any references to FWHM on some of the premium mount manufacturers websites that I checked. That doesn't mean it isn't out there, it's just that it doesn't appear to be a prominent selling point being used by them. If it is such a good measure of mount quality, then why is it not being pushed as such?


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David PavlichAdministrator
Transmographied
*****

Reged: 05/18/05

Loc: Mandeville, LA USA
Re: 10Micron new [Re: korborh]
      #6316642 - 01/16/14 02:27 PM

I don't speak for Ed, but I think what he's trying to convey is in order to get the most reliable data, variables have to be eliminated. In order to do that, you need to use one scope, one camera/filter combination, one imaging site and the most difficult, consistent atmospheric conditions...and, of course, the same person pulling the trigger. Once all of this is established, then you have to get the mount(s) for the comparison. And let's not forget that the tester can't go into the program with preconceived notions.

Because these variables can have a profound influence on the results, getting a RAW file from me in SE Louisiana is not going to have the same result as Jim Thommes in SoCal (Jim's would be better because he's way more talented than I am ).

In the end, the result would have to have an asterisk next to them explaining what may have caused the differences. I'm one of those guys that is concerned whether or not the picture I've taken is good enough to be placed in a frame and given to a family member or a friend and not be embarrassed. Blowing up an image to 500% to look at a star in the upper right hand corner that isn't perfectly round is not what I do. Maybe when I retire and have more time to mess with the end result, I will get a bit more critical of what I'm trying to do, but for now, my suburban backyard obs with my MI250 will do just fine.

David


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freestar8n
Post Laureate
*****

Reged: 10/12/07

Re: 10Micron new [Re: EFT]
      #6316689 - 01/16/14 02:45 PM

Umm... I just realized you are a vendor of the subject mount - which I did not know. I'm not talking about vendors or what they should do at all - and again - I am not demanding anything. I replied to someone who has the mount who was making some effort to provide images to demonstrate its performance, who also made statements with which I disagree.

I expect very little from vendors in terms of relevant information - but when they provide it I make note of it. Korborh has provided an example - and it scores points.

My interest is as a user of mounts striving for good guiding results, and as a potential buyer of a high end mount in the future. There are many imagers who get great results in an image and are happy to show the raw information and the fwhm's achieved. I'm very puzzled that you appear to be unfamiliar with this because I consider it a well known practice that people are proud to do when they invest a lot and have good results to show for it. I encourage others to judge mounts by quantitative performance metrics when available - and when users want to convey how well their mount performs - quantitative measures from raw images have benefits.

The OP asked about this particular mount, and in the same spirit I am asking for what I consider important ways to assess performance. If you as a vendor disagree with my criteria or my imaging aesthetics - that is perfectly ok with me.

Frank


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freestar8n
Post Laureate
*****

Reged: 10/12/07

Re: 10Micron new [Re: David Pavlich]
      #6316748 - 01/16/14 03:06 PM

Quote:

In the end, the result would have to have an asterisk next to them explaining what may have caused the differences.




When someone processes an image in arbitrary ways, and/or shows it with pixels that are so large they don't tell anything about the guiding performance, you need a huge, gigantic, towering asterisk next to the image. This isn't to say that doing that is bad to do - it's to say it obfuscates the contribution of the mount quality to the image.

Although seeing and other factors will affect fwhm - the standard mantra for someone getting into astrophotography is - get a good mount. This isn't just for usability - it's for *realized performance*. And realized performance shows in the sub-exposures. "You need a good mount."

The other issues of reliability and robustness - etc. - *also* don't show in an image. Showing a nice picture - especially a processed one - says nothing about those other metrics. They are nonetheless important and there are ways to describe them - but a picture doesn't really add much without details of the whole process, the setup, the software, etc.

One telling aspect of all this is when someone gets a good mount and shows a picture - people say things like, "wow - those stars are round" or "wow that's great guiding." Clearly those things are considered important, and are reasons high end mounts are coveted. Well - those things can be quantified in raw exposures so you know exactly how good they are.

It takes a few seconds to measure the fwhm, and whether or not people want to share it - I sure encourage people to measure theirs - if they are striving for best performance from their equipment at any price point. If they just want to image casually and have fun - that's fine, too.

Frank


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EFT
Vendor - Deep Space Products
*****

Reged: 05/07/07

Loc: Phoenix, AZ
Re: 10Micron new [Re: freestar8n]
      #6316821 - 01/16/14 03:50 PM

Quote:

Umm... I just realized you are a vendor of the subject mount - which I did not know. I'm not talking about vendors or what they should do at all - and again - I am not demanding anything. I replied to someone who has the mount who was making some effort to provide images to demonstrate its performance, who also made statements with which I disagree.

I expect very little from vendors in terms of relevant information - but when they provide it I make note of it. Korborh has provided an example - and it scores points.

My interest is as a user of mounts striving for good guiding results, and as a potential buyer of a high end mount in the future. There are many imagers who get great results in an image and are happy to show the raw information and the fwhm's achieved. I'm very puzzled that you appear to be unfamiliar with this because I consider it a well known practice that people are proud to do when they invest a lot and have good results to show for it. I encourage others to judge mounts by quantitative performance metrics when available - and when users want to convey how well their mount performs - quantitative measures from raw images have benefits.

The OP asked about this particular mount, and in the same spirit I am asking for what I consider important ways to assess performance. If you as a vendor disagree with my criteria or my imaging aesthetics - that is perfectly ok with me.

Frank




It's unfortunate that people don't (or can't) expect or trust relevant information from vendors since they have more access to the information than others. But it is understandably difficult to trust that source.

I do see some people occasionally provide FWHM data, but not that often. When it comes down to it, I would say that it is clear that many people don't really understand what it is in the first place (I'm certainly no expert). In regards to the specific mounts that are the subject of this thread, one thing you have to keep in mind is that there are very few owners here in the US and thus very few on CloudyNights to even answer the call at this point. There are certainly more extensive threads on European forms regarding these mounts and many more users overseas who might have the desired information, but there are obvious problems in getting that. In the mean time, with the small number of users of these mounts currently on CN, it is asking quite a bit for them to essentially sell the mounts. I appreciate everything these owners contribute here, but there is certainly no incentive for them to provide more (and there is frequently a disincentive to do so). The only people that really want to promote any particular mount are the people that make or sell them. The people that have already bought them are already convinced and don't necessarily feel the need to justify their purchase to others (or sell the products without a commission).

It is not that I disagree with your criteria, I just disagree with it as a single measure of the quality of a mount or that it can even be reproduced consistently. FWHM is but one factor that might (or maybe should) be considered in assessing the quality of a mount. It must be considered with other things and to many people it may not even be one of the most important criteria.

For example, if, as a dealer, I want to convince you to purchase a particular mount and there is specific criteria you need in order to make that decision, then it is up to me to decide whether I want to make the sale and if providing that information is worth making the sale, and then provide the information if I think it is. It is up to you to trust that I am providing it honestly. No one but me has the need to convince you of something and thus no one else is obligated to provide the information you want. The fact that this information is not available from, or being provided by the CN users of a particular mount, should not be viewed in any way as a reflection of the quality of the mount, but that is how it comes off (i.e., if no one will provide this information other the manufacturer, then there must be something wrong).

When someone posts a good image and takes the time to tell us how they got it and what equipment they used, the response does not need to be "show me the FWHM of the stars so that we all know it is a good as it can be." They have already provided what they feel, and many others agree, is the sufficient and pertinent information and they may not feel the need to give us more and they certainly are not obligated to.

We are not really in disagreement here, we are just coming at things from very different directions and for different purposes. With that said, we should let this thread get back on topic.

Ed.


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freestar8n
Post Laureate
*****

Reged: 10/12/07

Re: 10Micron new [Re: EFT]
      #6316915 - 01/16/14 04:43 PM

Sure, fwhm is one of many metrics - but it's a dang good one that is used consistently in professional work and by advanced amateurs. It has the same value in professional work as it does for amateur - assuming that amateur wants to get sharp images in long exposures.

I think that asking for fwhm is no different from asking for PE - except that PE involves much more work to characterize, and has little bearing on guided performance. For some reason it is perfectly fine to ask for PE values and logs and so forth, while fwhm is taken by some as an affront. I think this is a bizarre and backwards situation, and if someone wants to show a result and feels good about it - it is helpful to the community to communicate all relevant metrics - exposure time, site condition, equipment - and raw fwhm in arc-seconds. If someone doesn't want to do that - it is perfectly fine if they choose not to - just as they can choose not to describe any aspect of what they did. But if their goal is to express how well their equipment performs, and a processed picture is intended to do that - they would achieve their goal with trivial extra effort to state their raw fwhm, and with minor extra effort, as was done in this thread, to show a cropped section at full-res, but in a raw sub-exposure. I do not demand this - I encourage it, so that "that's great guiding" and "that must be a great mount" can have more meaning.

I perfectly understand a vendor's dilemma when it comes to such performance metrics because they can be skewed by ads and so forth. But when it comes to users sharing information with each other on CN - raw performance metrics would add to the impact that a good image is intended to have.

Frank


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orion69
scholastic sledgehammer


Reged: 05/09/10

Loc: Croatia
Re: 10Micron new [Re: freestar8n]
      #6316971 - 01/16/14 05:11 PM

If I own high-end mount like ASA or 10micron first thing what I would do after installing in my (not yet built) observatory is spend first good night testing in this way:

1. shoot 30 min unguided sub
2. shoot 30 min guided sub
3. shoot 30 min unguided sub
4. shoot 30 min guided sub
5. shoot 30 min unguided sub
6. shoot 30 min guided sub
(guided subs are using OAG)

Then I would compare RAW data (fwhm) from each sub and average from guided and unguided subs.
Then I'll repeat all that next night except first sub will be guided.

In my opinion that comparison will tell me if mount can be used for long unguided subs and ultimately if I would be better with high end mount without absolute encoders and more capacity.

Of course I don't demand anything, that is what I would do.


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Skunky
sage


Reged: 09/16/13

Re: 10Micron new [Re: orion69]
      #6317181 - 01/16/14 07:01 PM

Isn't Frank a vendor too? I don't think offering software free should determine whether you are a vendor or not.. I mean Frank is pretty partial to his own software, Metaguide... Is metaguide open source? If so then I see why Frank would not be considered a vendor.

I don't think Ed should be considered a vendor in this thread.. He's giving away "free" advise... Frank gives away "free" advise as well to steer users towards his "free" software... I don't see much of a difference... Or both are vendors because neither can give impartial advise..





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